ISTANBUL — As Jamal Khashoggi prepared to enter the Saudi consulate in Istanbul on Oct. 2, a squad of men from Saudi Arabia who investigators suspect played a role in his disappearance was ready and in place.

They had arrived from Riyadh, the Saudi capital, early that morning and checked in at two inter­national hotels in Istanbul before driving to the consulate in the leafy Levent neighborhood, said two people with knowledge of the investigation. One of them, the Mövenpick Hotel Istanbul, is a few minutes from the consulate by car.

By the end of the day, a 15-member Saudi team had conducted its business and left the country, departing on planes bound for Cairo and Dubai, according to flight records and the people familiar with the investigation.

Turkish officials have previously said they believe that Khashoggi, a prominent journalist and critic of the Saudi government, was killed inside the consulate.

Turkish officials, who are examining the squad’s movements, have now expanded their investigation to explore what happened at the residence of the Saudi consul general, Mohammed al-Otaibi, located 500 yards from the consulate. A photograph taken from a Turkish police closed-circuit television camera outside the residence and obtained by The Washington Post shows a Mercedes Vito van with tinted windows that security officials say transported some of those men from the consulate to the residence about two hours after Khashoggi entered the consulate.

In the week since the disappearance of Khashoggi, a contributor to The Post’s Global Opinions section, the Saudi government has maintained that he left the consulate soon after he arrived. Not only do they not know what happened to him, they say, but they are also worried for his safety.

“It goes without saying that his family in the Kingdom remain gravely concerned about him, and so are we,” the Saudi ambassador to Washington, Khalid bin Salman, wrote in a message that was shared with the news media on Monday.

Before Khashoggi’s disappearance, U.S. intelligence intercepted communications of Saudi officials discussing a plan to capture him, according to a person familiar with the information. The Saudis wanted to lure Khashoggi back to Saudi Arabia and lay hands on him there, this person said. It was not clear whether the Saudis intended to arrest and interrogate Khashoggi or to kill him, or if the United States warned Khashoggi that he was a target, this person said.

Saudi officials, however, have denied reports that they sent a 15-man team to Istanbul on the day Khashoggi disappeared, saying that the only team they sent to Turkey consisted of investigators who arrived Saturday to help find the journalist.

According to flight records, two privately owned planes flying from Riyadh arrived in Istanbul on Oct. 2, one before sunrise and the other in the late afternoon. A Turkish official linked the call signals of the two twin-engine Gulfstream IV planes to those that investigators believe carried the 15 Saudis. The planes are owned by Riyadh-based Sky Prime Aviation Services, according to public records.

Flight data collected by AirNavRadarBox, a firm that tracks private and commercial planes all over the world, showed that the first of the two planes left Riyadh late Oct. 1 and touched down in Istanbul the following day at 3:15 a.m.

They checked into the Mövenpick, one of the people with knowledge of the investigation said. Management at the five-star hotel said they were not allowed to confirm or deny that the group had checked in or that their hotel was part of the investigation. A hotel worker confirmed that the group checked in Tuesday. “The police came two or three days ago,” he said.

The first plane was carrying the part of the Saudi team that was awaiting Khashoggi at the consulate, investigators believe, when he arrived at 1:14 p.m. to collect a document he needed for his upcoming marriage.

Turkey’s government says it has seen no evidence supporting the Saudi claim that Khashoggi ever left the consulate alive.

Turkish police operate at least one camera at the front of the building. Investigators have also examined footage that covers the rear of the mission. Closed-circuit TV camera feeds from the preschool opposite the rear entrance have been retrieved by Turkish intelligence, and images from outside the hotels are also being reviewed, according to people familiar with the probe.

A camera recorded Khashoggi entering the consulate at 1:14 p.m., but he was never seen leaving.

“It’s clear he did not exit,” said one Turkish official with knowledge of the investigation, who spoke on the condition of anonymity to discuss the ongoing investigation.

Behind a gate next to the front entrance is a covered car port, out of the view of cameras. From that garage, two vehicles exited about two hours after Khashoggi entered the consulate, according to one of the people briefed on the investigation. One of the cars was the Mercedes that pulled up in front of the residence of Otaibi, the Saudi consul general, at 3:09 p.m., according to the time stamp on the video still of the Mercedes obtained by The Post.

The drive to the consulate takes only a few minutes. The building is topped with the Saudi emblem of golden crossed swords and a palm tree. A Saudi flag flies outside. Two private security guards in a booth outside confirmed that the video still appeared to be shot from a camera that belonged to the police.

The cars stayed at Otaibi’s residence for four hours, according to an account published Tuesday in Sabah, a pro-government Turkish newspaper connected to President Recep Tayyip Erdogan. The report added that Turkish employees at the residence were “hastily” told to leave that day. The veracity of the report could not be confirmed.

Flight data shows that a second private jet, believed by investigators to be transporting the rest of the team, touched down in Istanbul at 5:15 p.m. It is unclear whether those on board traveled to either the consulate or the residence. It departed an hour and 15 minutes after it arrived, heading for Cairo. Twenty-five hours after its arrival in Cairo, the plane left for Riyadh.

The initial plane left Istanbul at 10:45 p.m. and made a stop about 170 miles to the east in Nallihan, Turkey. Then it skirted the border between Iraq and Iran, favoring the Iraqi side, and crossed over the Persian Gulf. It landed in Dubai at 2:30 a.m. The following morning, Oct. 3, it took off for Riyadh.

Correction: An earlier version of this article gave an inaccurate description of how far Nallihan is from Istanbul. The distance is about 170 miles.